In previously known analyzers, the reagents needed for analysis are generally stored in bottles or in specially shaped containers or reagent vessels. From these, the reagent is transferred into the analyzing process either by suction through a hose permanently connected to the bottle or by inserting through the bottle mouth a dosing needle into which the reagent is drawn and from which it is passed further into the analyzing process. The bottles or vessels are stored either in a fixed storage space, often provided with a cooling system, or in a movable disc, usually rotatable. In the case of a discoid storage, an optimum space utilization is achieved if the vessel has the shape of a sector. Sector-shaped vessels allow the most efficient utilization of a circular storage area.
Sometimes, however, there is a need to use a different type of vessels, e.g. round bottles, to store reagents. The need for a round bottle may arise e.g. from the fact that it is not economically or otherwise sensible to store a small volume of reagent in a sector-shaped vessel or that a glass bottle is the best or even the only solution to ensure stability of the reagents.
If a sector-shaped vessel and a round bottle are to be firmly positioned in the same frame, this generally requires a separate guide to surround the round bottle with a body of partly or completely sectorial shape. As the space utilization in a round disc has been designed for a sectorial vessel, positioning a round bottle firmly in it without a separate guide is generally not possible.